How to Fix a Key Fob That isn't Working
If your key fob isn't working There are a few simple steps that can fix it. The first step is to be sure that it's not your backup remote.
If your backup remote is unable to lock and unlock the doors of your car, it is most likely that the primary remote isn't functioning. Most car remote key failures result from battery or circuitry problems.
Battery
It is not uncommon for the battery in the car key fob to get worn out. It is easy to replace the battery. However, it is important that you use the correct type. You can refer to your owner's manual or call the manufacturer to determine the right kind. It is recommended to examine the battery compartment thoroughly, as dead batteries sometimes leak caustic chemicals that can damage the remote. If changing the battery doesn't fix the issue there may be additional issues that require professional attention. For instance, if buttons appear stuck or broken, it may be necessary to disassemble the remote and rebuild its components. It is also possible to reprogramme the vehicle to recognize the new fob.
Buttons
Key fobs may become dirty and worn out from frequent use. This is not unusual however, it can cause buttons to cease working or require a hard press for them to function. This can be very frustrating particularly if you're away from home and you need to start your vehicle. Even broken or damaged buttons can be fixed with a bit of time and materials you already have at home.
First, ensure that the batteries are charged correctly and that the indentation on the back of the button is filled. Then, carefully remove the remote and examine the circuit board. Examine for signs of rust or other indications that the buttons are damaged or worn. For example the paint that conducts electricity could be missing. Use a Q-tip that has been dipped in alcohol to gently clean any membrane contact that has become worn out or where conductive paint is missing. Don't rub too hard, as this could erode the conductive paint and prevent the button from firing when you press it.
Also, be sure to check the battery connector's terminals for any loose solder connections. If this is the case, simply reconnecting them may restore functionality to the button. You can use the same procedure to restore functionality to any other loose connection inside the fob.
If any of the rubber buttons located at the front of the keyfob isn't working or require being pressed extremely hard the graphite disks at the back of the button might have worn out and will need to replaced. You can do this by rubbing a pen across the disks. This should bring the button back to life.
If none of these solutions work or you are unable to get the button to respond when you press it hard, it could be that the circuitry is failing. This can be fixed by a quick clean and refitting, but it's best to have an extra fob available in the event this method doesn't work for you.
Circuitry
The circuit board in the remote control could be dirty, regardless of whether the buttons on the key fob function or not. A thorough inspection will usually resolve this issue. Broken cases and water are the most common causes of boards that are dirty. key fob repair service broken case allows water and other debris to pass through and short circuit the electronic components. Water can also get through pins and vias, which are the tiny connectors on the board.
If you're handy enough to open up your key fob and don't mind a little mess, we can remove the solder from the buttons and then solder new ones in their place. Also, you should check the connections between battery terminals. They can become very dirty and if they're loose, the buttons might not function or even stay in their down position. Soldering the terminals and buttons to their proper positions is usually enough to return a malfunctioning fob to working.
Non-Remote transponder chips
The sealed non-remote chips are more durable than remote fobs. However, they can be cracked in the event of a hole being drilled in them, or in the event that a door handle of a car or lawnmowers plows over them. Fuse failures are usually to blame for non-remote chips failures.
If you're not confident opening the key fob, remove the circuitboard and use a multimeter to check that the diode is working properly. If you're not confident doing this, head to your local hardware store or Oreilly's, and they usually have a radio frequency tester that can tell you whether the key fob sending signals.
Programming
Key fobs endure a lot of abuse and aren't indestructible. They can lose their pairing to the car's receiver due to shock or a low battery, which calls for them to be reprogrammed. A professional auto locksmith or main dealer can reprogram your key fob and get it functioning again. In the rarer case that resetting or repairing your key fob isn't working, it could be time to replace it completely.